National Oceanic and Atmospheric Administration National Weather Service United States Department of Commerce
Current conditions at

Islip, Long Island Mac Arthur Airport (KISP)

Lat: 40.79°NLon: 73.1°WElev: 98ft.

Mostly Cloudy

70°F

21°C

Humidity 49%
Wind Speed N 7 mph
Barometer 30.13 in (1020.1 mb)
Dewpoint 50°F (10°C)
Visibility 10.00 mi
Last update 13 Jun 7:56 am EDT
Extended Forecast for

Ronkonkoma NY

  • Today

    Today: Partly sunny, with a high near 77. Northeast wind 5 to 8 mph becoming southeast in the afternoon.

    High: 77 °F

    Partly Sunny

  • Tonight

    Tonight: A slight chance of showers and thunderstorms, then showers likely after 2am. Mostly cloudy, with a low around 62. East wind around 7 mph. Chance of precipitation is 70%.

    Low: 62 °F

    Slight Chance
    T-storms then
    Showers
    Likely

  • Saturday

    Saturday: Showers likely, mainly before 2pm. Cloudy, with a high near 68. Northeast wind 10 to 14 mph. Chance of precipitation is 60%. New precipitation amounts between a quarter and half of an inch possible.

    High: 68 °F

    Showers
    Likely

  • Saturday Night

    Saturday Night: A 30 percent chance of showers, mainly before 2am. Cloudy, with a low around 58. Northeast wind around 10 mph.

    Low: 58 °F

    Chance
    Showers

  • Sunday

    Sunday: A slight chance of showers before 8am, then a slight chance of showers after 2pm. Mostly cloudy, with a high near 70. Northeast wind around 11 mph. Chance of precipitation is 20%.

    High: 70 °F

    Mostly Cloudy
    then Slight
    Chance
    Showers

  • Sunday Night

    Sunday Night: A 30 percent chance of showers after 8pm. Cloudy, with a low around 59.

    Low: 59 °F

    Chance
    Showers

  • Monday

    Monday: A 40 percent chance of showers. Mostly cloudy, with a high near 71.

    High: 71 °F

    Chance
    Showers

  • Monday Night

    Monday Night: Mostly cloudy, with a low around 62.

    Low: 62 °F

    Mostly Cloudy

  • Tuesday

    Tuesday: Mostly cloudy, with a high near 77.

    High: 77 °F

    Mostly Cloudy

Detailed Forecast

Today
Partly sunny, with a high near 77. Northeast wind 5 to 8 mph becoming southeast in the afternoon.
Tonight
A slight chance of showers and thunderstorms, then showers likely after 2am. Mostly cloudy, with a low around 62. East wind around 7 mph. Chance of precipitation is 70%.
Saturday
Showers likely, mainly before 2pm. Cloudy, with a high near 68. Northeast wind 10 to 14 mph. Chance of precipitation is 60%. New precipitation amounts between a quarter and half of an inch possible.
Saturday Night
A 30 percent chance of showers, mainly before 2am. Cloudy, with a low around 58. Northeast wind around 10 mph.
Sunday
A slight chance of showers before 8am, then a slight chance of showers after 2pm. Mostly cloudy, with a high near 70. Northeast wind around 11 mph. Chance of precipitation is 20%.
Sunday Night
A 30 percent chance of showers after 8pm. Cloudy, with a low around 59.
Monday
A 40 percent chance of showers. Mostly cloudy, with a high near 71.
Monday Night
Mostly cloudy, with a low around 62.
Tuesday
Mostly cloudy, with a high near 77.
Tuesday Night
Mostly cloudy, with a low around 64.
Wednesday
Mostly cloudy, with a high near 79.
Wednesday Night
Mostly cloudy, with a low around 67.
Juneteenth
A 30 percent chance of showers and thunderstorms. Partly sunny, with a high near 83.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Ronkonkoma NY
 40.81°N 73.11°W (Elev. 98 ft)
Last Update:
3:44 am EDT Jun 13, 2025
Forecast Valid:
8am EDT Jun 13, 2025-6pm EDT Jun 19, 2025
 
Forecast Discussion
 
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Additional Resources

Radar & Satellite Image

Link to Local Radar Data Link to Satellite Data

Hourly Weather Forecast

National Digital Forecast Database

National Digital Forecast Database Maximum Temperature Forecast

High Temperature

National Digital Forecast Database Weather Element Forecast

Chance of Precipitation